The present invention relates to DVD-RAM, and more particularly, to a method for dynamically adjusting a header region RF gain of a variable gain amplifier while accessing header regions of a DVD-RAM disc, and apparatus thereof
There are many different types of DVD standards that are currently utilized, including: a DVD±R standard, a DVD-RAM standard, and a DVD±RW standard. According to the DVD-RAM standard, a DVD-RAM disc includes a plurality of sectors. FIG. 1 shows a sector of a DVD-RAM disc. The sector consists of a header region and a recording region. The header region includes an upper header and a lower header; each of them contains two headers. In other words, a header region contains four headers. These headers are: a header1, a header2, a header3, and a header4. The data layout of a header region is illustrated in FIG. 2.
The header regions and recording regions of a DVD-RAM disc normally have different reflectance. Hence, an optical disc drive of a related art always utilizes two different RF gains to access the DVD-RAM disc; a header region RF gain is utilized when the header regions of the DVD-RAM disc are accessed and a recording region RF gain is utilized when the recording regions of the DVD-RAM disc are accessed. In addition, reflectance of different recording regions on different track positions does not always maintain a fixed value. Hence, for accessing data more accurately, the optical disc drive of the related art dynamically adjusts the recording region RF gain.
In actuality, reflectance of different header regions on different track positions does not always maintain a fixed value either. Unfortunately, many optical disc drives on the market are not capable of adjusting the header region RF gain dynamically when accessing header regions of DVD-RAM discs.